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Inaccurate Trip Computer?
Posted: Tue May 06, 2008 4:58 am
by weekender
Hi all,
I am the proud new owner of my new Matt Silver R1200r - I have owned 2 previous BMW's in the past - a R100 GS Paris Dakar that I rode around Australia (even up to Cape York) and later an R1100 GS. All of that was a while ago - and I haven’t had a bike for about 10 years.
Anyway- the other weekend I relied a bit too much on the trip computer and ran out of fuel when the trip computer said that it still had 22 km's to go. It ran out 12kms out of Nowra in NSW.
It was at about that time when my already reluctant pillion lost their sense of adventure.
I did get to try the BMW assist line - I was on the road again in about 1 1/2 hours.
Has anyone else had a similar experience?
Other options include:
ABS/ASC/Centre Stand/White Lenses/Panniers/Tyre Pressure Sensors
Re: Inaccurate Trip Computer?
Posted: Tue May 06, 2008 6:13 am
by hankth
I have run mine down to 23 miles range left with no problem. I realize that is more than 22K. Chalk it up to a learning experience about your bike. ride safe.
Re: Inaccurate Trip Computer?
Posted: Tue May 06, 2008 7:36 am
by MJB
Did your low fuel light come on?
I have run mine down to about 40k left showing on the computer.
My rule is to always try to fill up before the low fuel light comes on....you never know.
The reason I was down to about 40k left, was because I was out in the country and went to fill up, and the gas station was closed. Had to scramble to find another one…
I think the computer is a good gauge, however I would never intentionally want to have only about 1 liter of gas left in the tank...
Re: Inaccurate Trip Computer?
Posted: Tue May 06, 2008 8:25 am
by lucagoa
MJB,
fully agree with you. Computer's nice stuff but I always refill when I'm about 40 to 50 km left
Let's say I'm a bit on the safe side

Re: Inaccurate Trip Computer?
Posted: Tue May 06, 2008 9:01 am
by famousperson
Since my computer's mileage calculation is off (last fill-up it said 44 mpg when my hand calculation was 55 mpg) I don't trust the fuel gauge or "distance remaining" screen, either. I do a mental calculation using 45 mpg and 5 gallon capacity to give myself a good margin. Of course, in the Western Pennsylvania "outback" I am never more than 10 miles, probably more like 5, from a gas pump, and cell coverage is virtually total, it isn't nearly so critical as it most likely is for you.
Since my last bike (H-D Sportster) had a 3 1/2 gal. tank and I couldn't count on more than 40 mpg, I am used to filling early and often. Being able to count on at least 200 (333 km) miles per tank with the R is pure luxury.
Re: Inaccurate Trip Computer?
Posted: Wed May 07, 2008 5:43 am
by weekender
Thanks all for your feedback - Ill put it down to extreme experimentation- and won't run it that light again.
Good riding all -
Cheers.
Re: Inaccurate Trip Computer?
Posted: Wed May 07, 2008 9:14 am
by icecave
I find the "computer" is doing a pretty good job of guesstimating the remaining fuel on my bike having done a fair amount of testing with the yellow need fuel light coming on. You'll note that running average shown for mpg (over a tank full of gas) is different if you keep reseting the average MPG to give you a "peak" MPG. Peak MPG being the preferred usage when in a low fuel situation.
When combined with the trip odometer (reset or know at last fueling) and the always "accurate sloshing the tank" to hear the remaining fuel one can effectively use the reserve tank out here in the West where cell phones don't work and signs like no fuel or services for 80 miles are common. During the energy shortage of the '70, interstate travel was dicey and I got use to driving around on "empty" in the car. I haven't tried this on the bike, but the use of a wooden stick (yard stick was the best) dipped in the tank provided a very accurate picture of fuel remaining on my old dirt bikes.
Re: Inaccurate Trip Computer?
Posted: Wed May 07, 2008 10:45 am
by deilenberger
Since we're on the topic - what's the most you've put in the tank?
I seem to remember around 5.2 gallons.. that was with 20 miles left indicated IIRC.
Re: Inaccurate Trip Computer?
Posted: Wed May 07, 2008 10:58 am
by eisen
deilenberger wrote:Since we're on the topic - what's the most you've put in the tank?
I seem to remember around 5.2 gallons.. that was with 20 miles left indicated IIRC.
A touch under 5 gallons (around 18 litres) with roughly 40km to empty.
I don't like riding with the reserve light on...
Re: Inaccurate Trip Computer?
Posted: Wed May 07, 2008 11:49 am
by icecave
I recall around ~5.2 gallons with under 15 miles (12-13?). Getting a consistent "fill-up" to bottom of the red plastic fill in problematic. I find wrestling with the gas vapor interlock on the pump handle and fueling a real challenge on the bike.
An interesting data point would be the various in trip points for the fuel warning light. How much fuel did you put in when the light turns on?
Re: Inaccurate Trip Computer?
Posted: Mon May 26, 2008 5:06 pm
by icecave
FYI, trip computer indicated I had 19 miles to go on the tank. I was able to fill the bike with 5.34 gallons with side kick stand down. Sadly that equates to $23.04 @ $4.315/gal for premium (92 octane). Good news >50 mpg on this tank full.
Re: Inaccurate Trip Computer?
Posted: Tue May 27, 2008 2:01 am
by ShinySideUp
Besides running out of gas in the middle of the night with coyotes howling, I've found another reason not to test the limits of the computer's accuracy: When my fuel gets low (light on for some time) and I accelerate hard, the gas sloshes back away from the tank outlet and the engine cuts off. Not a good thing, if the reason for accelerating fast is to get out of some cager's path.
When the light comes on, I find a gas station.
Re: Inaccurate Trip Computer?
Posted: Tue May 27, 2008 3:37 am
by yim4
I have tested the limits of the trip computer and ran out of gas with 10 miles left on the computer. Oops. Thankfully the engine died as I was pulling into my destination.
Re: Inaccurate Trip Computer?
Posted: Tue May 27, 2008 9:41 am
by mtl-R12R
I actually went past the mileage count down. I had to stretch it, late at night, and my intended gas stop was closed.
I watched the count down go to 1km, and then just ended up with lines in the display instead of numbers. I did another 5 kms till I managed to find gas.
and for those that like introductions, Howard, from Montreal, thoroughly enjoying his 08 granite R12R

Re: Inaccurate Trip Computer?
Posted: Tue May 27, 2008 10:41 am
by icecave
Howdy Howard and welcome aboard the R1200R experience. I glad your end of gas story ended happily.
Ideally, we would do this type of testing with a small gas can attached to the bike or no further from a gas station than one cares to push the bike too. Typical country rides I'm looking for gas stations at 70 miles out and definitely when the yellow light comes on, the computers reports about 40 mile range at that time. In these changing times, finding an open gas stations can be problematic. Tainted gasoline is another issue around here:
http://seattlepi.nwsource.com/local/364 ... ate27.html